Field of the Invention
The invention relates to a device for comminuting feedstock.
Description of the Background Art
Such devices fall within the field of mechanical process engineering, particularly the comminution of feedstock by means of cutting, shearing, tearing, or breaking up. But the breaking of the bond of composite materials, with which a comminution of the feedstock always proceeds, is also within the scope of the present invention. Within the meaning of the invention, prior-art devices are, for example, shredders, cutting mills, hammer mills, and the like. Generic devices therefore are suitable for comminuting piece and bulk goods, particularly plastics with and without admixtures, wood, scrap wood, paper, cardboard, cellulose, textiles, waste materials, rubber, natural rubber, resins, leather, foodstuffs, semi-luxury food, and feedstuffs, minerals, pigments, dyes, pharmaceuticals, metals, composite materials such as electronic waste, cables, used tires, and the like. Other feedstock originates from the recovery of reusable materials during recycling, for example, for their reuse as alternative fuels.
The basic principle of material processing results from the interaction of rotating cutting, shearing, or tearing tools with stationary tools or, however, from the impact energy of rapidly rotating impact tools such as hammers, plates, and the like, which break up the feedstock. After sufficient comminution, the feedstock is removed from the device via a screen deck, whereby the screen deck can function in addition as a comminution tool. The screen therefore divides the housing interior functionally into an upstream comminution region and a downstream comminution region for the removal of already comminuted material.
US 200600118671 A1 discloses a generic device having a rotor-accommodating housing. The rotor is formed by a drive shaft on which a plurality of rotor discs sit concentrically. The rotor discs are equipped over their circumference with tooth-like comminuting tools and act together with stator tools disposed in a stationary manner in the housing. A wear ring is disposed concentrically to the drive shaft in each case on the front rotor discs of the rotor. The rotor penetrates the housing in the axial direction, to which end the housing walls have circular openings. The rotor is mounted in bearings outside the housing.
A screen deck, having screen supports and a perforated screen, extends over the rotor circumferential section running below the drive shaft, whereby the perforated screen while maintaining a radial distance follows the outer circumference of the two wear rings, so that a sealing gap through which accordingly small particles in the feedstock can leave the housing results between the perforated screen and wear rings.
Because the partially cylindrical shape of the perforated screen is produced by rolling, production-related tolerances result with respect to the curvature of the perforated screen. Subsequently, the perforated screen and the wear ring do not run constantly parallel to one another, but the radial width of the sealing gap varies over the circumference of the perforated screen. In areas where the sealing gap is wider, a negative effect on the sealing action therefore cannot be prevented. A further disadvantage is that because of the design type the gap always aligns axially with the inner circumference of the perforated screen. The operator of such a device is therefore restricted to this machine geometry.